2 Answers

Web of Trust is an entirely different thing from anti-virus. There will be no conflict as they do such entirely different things. However, from what I’ve heard of that particular add-on, it’s more of an opinion poll than a piece of security software, and will not really provide you with actual protection. It’s fine if you like your internet censored based on the political beliefs or entertainment opinions of others, but not if you are interested in avoiding sites known to infect computers with malware.

Avast! antivirus has a similar tool built-in, as do AVG, Norton and McAfee (though Avast! is the only one of the four antivirus programs I would trust.) if you are interested in an all-in-one solution that has zero chance of conflicting with itself. More importantly, ratings are based more on security than on popularity.